Lockers at park entrance... Will Carryon fit?

[HillsboroHoppers]

Going to US/IOA for first time Sept 22-26. For budgetary reasons we are staying off-site. Are the lockers at the front gate large enough to stow a carry on bag? We don't fly out until 6pm on the Sunday, and would like to spend most of the day at the parks, then take a cab to MCO. We travel only with a carry on. Any other storage options if the lockers are too small? Also, are taxis readily available or do I need to schedule transportation from the park to MCO?

Thanks!